The Clinical Value Of Bronchodilator Reversibility Testing In Small Airway Disease

ObjectiveWe studied the positive rate of bronchodilator reversibility testing and the incidence of asthma in patients with small airway disease in order to explore the clinical value of bronchodilator reversibility testing in small airway disease and the predicting value of small airway diseases for asthma.Methods104patients with small airway disease were selected on the basis of diagnostic criteria of small airway disease,152patients with normal ventilation function were selected as control group. All bases were examined by spirometry and bronchodilator reversibility testing, then the results were recorded and analyzed.We calculated the positive rate of bronchodilator reversibility testing.The outcomes of the all patients were tracked to make sure the incidence of asthma.The patients with small airway disease were divided into3groups,children group,young and middle-aged group,old group.We compared the positive rate of bronchodilator reversibility testing and the incidence of asthma among the three groups.ResultsThe positive rate of bronchodilator reversibility testing in patients with small airway disease and control group were31.7%and7.9%.There are statistics significance between two groups (x2=24.215, P<0.05). The incidence of asthma in two groups were22.1%and4.6%, There are statistics significance between two groups (x2=18.301, P<0.05).There was significant difference in pre-bronchodilator FEF25-75%、FEF50%、FEF75%measurement between positive group and negative group in patients with small airway disease (P<0.05). Pre-bronchodilator FEF25-75%、FEF50%、FEF75%measurement were negatively correlated with improvement rate and absolute change of FEV1measurement,and the correlation of the pre-bronchodilator FEF25-75%measurement is better. There was significant difference in the positive rate of bronchodilator reversibility testing among children group,young and milldle-age group and old group (x2=14.147, P<0.05).There was no difference between the children group and young and milldle-age group. There was significant difference between the children group and old group (x2=9.378, P<0.0167).There was significant difference between the young and milldle-age group and old group (x2=10.381, P<0.0167). The positive rate of bronchodilator reversibility testing of the children group and young and milldle-age group were higher than old group. The incidence of asthma of children group,young and milldle-age group and old group were41.7%,36.4%,10.2%.There was significant difference in the incidence of asthma among3groups (x2=13.291, P<0.05).There was no difference between the children group and young and milldle-age group There was significant difference between the children group and old group (x2=6.543, P<0.0167).There was significant difference between the young and middle-age group and old group (x2=10.927, P<0.0167). The incidence of asthma of the children group and young and middle-age group were higher than old group.Conclution1. The positive rate of bronchodilator reversibility testing of patients with small airway disease was higher than control group, there may be the predicting value for reversible airway obstruction to patients with small airway disease through bronchodilator reversibility testing. 2. The pre-bronchodilator FEF25-75%、FEF50%、FEF75%measurement of positive group in patients with small airway disease were lower than negative group.The more terrible the small airway was damaged,the more possible asthma happen.3. Pre-bronchodilator FEF25-75%、FEF50%、FEF75%measurement were negatively correlated with improvement rate and absolute change of FEV1measurement, and the correlation of the pre-bronchodilator FEF25-75%measurement is better.4. The incidence of asthma in small airway disease group was higher than the control group, asthma maybe merge with small airway disease,the applicationg of bronchodilator reversibility testing in small airway disease may have predictive value to the incidence of ssthma.5. Compared to the older patients with small airway disease, the application of bronchodilation testing in children and young and middle-aged patients with small airway disease may have more predictive value to the occurrence of asthma, but there is no difference between children and young and milldle patients.